This invention relates to a method for weaving fabrics with a rib structure, whereby on a weaving machine a backing fabric is woven out of weft yarns and warp yarns, and whereby warp yarns are alternately woven into in the backing fabric and are rib-formingly passed around over at least one weft yarn extending on the backing fabric surface.
This invention also relates to fabrics with a rib structure and more especially to fabrics which approximate the appearance of a loop pile fabric or bouclxc3xa9 fabric, and are in general referred to by the name of xe2x80x9cfalse bouclxc3xa9 fabricsxe2x80x9d, in which rib warp yarns are alternately woven into in the fabric and are rib-formingly passed around at least one weft yarn.
This invention relates in particular to a so-called false bouclxc3xa9 carpet and a weaving method for manufacturing such a carpet.
According to a known method for manufacturing these types of carpets on a weaving machine a series of warp yarn systems are provided each of which comprises two pattern warp yarns, and in successive weft insertion cycles in each case two weft yarns are inserted one above the other in respective sheds between these warp yarns. With each weft insertion the warp yarns are brought into such positions in relation to the weft insertion levels that the pattern warp yarns bind the weft yarns, so that a fabric is formed, in which tension warp yarns are woven into, in which the pairs of weft yarns inserted in successive cycles extend alternately above and below these tension warp yarns, in which per warp yarn system a first pattern warp yarn extends alternately above a pair of weft yarns extending along the upper of the fabric and between the weft yarns of a pair of weft yarns located along the back side of the fabric, and a second pattern warp yarn extends alternately between the weft yarns of a pair of weft yarns located along the upper of the fabric and under a pair of weft yarns extending along the lower side of the fabric. A fabric is thus obtained of which both the upper and the back side show a rib structure. In the course of the successive weft insertion cycles a rib line is produced alternately along the upper side and along the back side of the fabric. If the first and the second pattern warp yarn have a different color a two-color design or pattern can be made visible on the upper side of the fabric. On the back side of the fabric a type of negative (with swapped colors) is obtained of the design which is visible on the upper side of the fabric.
A disadvantage of this weaving method is that it only enables a medium productivity. Furthermore the patterns or designs provided on these fabrics only have two different colors.
The purpose of this invention is to provide a method for manufacturing a fabric with a rib structure, with which on the one hand a higher productivity can be achieved and with which on the other hand more variation can also be brought into the appearance of the fabric.
This objective is achieved according to this invention with a method having the characteristics mentioned in the first paragraph of this specification, by weaving two fabrics one above the other with a rib structure according to a face-to-face weaving method, while warp yarns are alternately interlaced in the top and the bottom fabric around at least one weft yarn, and cutting through these warp yarns between the two fabrics so that each fabric with a rib structure also comprises at least one area with cut pile yarns.
According to this method two fabrics with a rib structure are woven simultaneously so that the productivity is doubled in comparison to existing methods. The one or several area(s) with cut pile provide a much more varied appearance of the fabric top. The rib structure gives a bouclxc3xa9 effect (this is the effect of a loop pile fabric) in the fabric, while the cut pile produces a so-called plush effect (the effect of a pile or velvet fabric). According to this weaving method false bouclxc3xa9 plush carpets can more specifically be woven in a very productive manner.
With this method preferably two backing fabrics located one above the other are woven respectively out of weft yarns and binding warp yarns, while the weft yarns over which warp yarns are rib-formingly passed around extend outside these backing fabrics over the backing fabric surface. Because of this these weft yarns come to lie higher so that a clearer rib structure is obtained.
If these warp yarns are furthermore rib-formingly passed around over weft yarns which belong to a set of at least two weft yarns located one above the other, still higher ribs are obtained so that a very clear rib structure is obtained.
For example a set of weft yarns located one above the other and one single interjacent weft yarn can be provided alternately in each fabric.
In order to achieve a very clear bouclxc3xa9 effect for the weft yarns over which ribs are formed a thicker weft yarn is used than for the other weft yarns. This makes the rib height still higher.
It is furthermore also preferable to inweave tension warp yarns into each backing fabric.
In order to weave fabrics of a high quality, non-rib-forming and non-pile-forming warp yarns are divided among the top and the bottom fabric woven into these fabrics, and moreover extend between the weft yarns over which ribs are formed and the other weft yarns (woven into in the backing fabric) of the fabric.
These woven in warp yarns hold the weft yarns, over which ribs are formed, well out of the backing fabric through which a pronounced bouclxc3xa9 effect is obtained.
According to a first preferred method the weft yarns are in the course of successive series of four successive operating cycles of the weaving machine weft insertion means inserted in respective sheds between the warp yarns, whereby in the first cycle of each series one weft yarn is inserted for the top fabric, in the second cycle of each series one weft yarn is inserted for the bottom fabric, in the third cycle of each series two weft yarns are inserted one above the other for the top fabric, and in the fourth cycle of each series two weft yarns are inserted one above the other for the bottom fabric.
The weaving machine utilized for this method is preferably provided with two weft insertion means in order to insert two weft yarns one above the other in the course of the same operating cycle. In the course of the cycles in which only one weft yarn is inserted, one of the two weft insertion means is then disengaged or no weft yarn is proferred to one of these weft insertion means.
According to a second preferred method the weft yarns are in the course of successive series of two successive operating cycles of the weaving machine weft insertion means inserted in respective sheds between the warp yarns, whereby in each series in one cycle two weft yarns are inserted one above the other for the bottom fabric and one weft yarn is inserted for the top fabric, and in the other cycle two weft yarns are inserted one above the other for the top fabric and one weft yarn is inserted for the bottom fabric.
This method is very efficient. Per two successive weft insertion cycles a rib line can be produced at the same time in two fabrics. In comparison to the above described first preferred method this method doubles the productivity.
The weaving machine utilized for this method in preferably provided with three weft insertion means in order to insert three weft yarns one above the other in the course of the same operating cycle.
In order to achieve the effect of long loops at least one warp yarn can be allowed to extend rib-formingly over two or more successive weft yarns of a fabric without interjacent interlacing in the fabric.
This invention also relates to a fabric with a rib structure, in particular a false bouclxc3xa9 fabric, as described in the second paragraph of this specification, which also comprises at least one area with cut pile.
The fabric according to this invention is preferably manufactured according to the method of this invention, and is in its most preferred form a so-called false bouclxc3xa9 carpet with plush effects.
In that which follows two methods according to this invention are described in detail. The purpose of this specification is only to clarify further the aforesaid characteristics of the method and of the fabrics manufactured according to this method, and to specify further properties and distinctive features thereof, and may therefore in no way be considered as a restriction on the protection claimed for this invention in the claims of this patent application.
In this specification reference is made by means of reference numbers to the figures attached hereto, of which
FIG. 1 is a schematic cross-section according to the warp direction of a false bouclxc3xa9 carpet that has been woven according to a first method according to this invention.
FIG. 2 is a schematic cross-section according to the warp direction of a false bouclxc3xa9 carpet that has been woven according to a second method according to this invention.
According to a first preferred weaving method according to this invention use is made of a known face-to-face weaving machine with a weft insertion mechanism that comprises two rapier devices operating one above the other which are controllable in order in each operating cycle to bring a respective weft yarn through a shed between warp yarns, and furthermore also comprises a presenting means for each rapier device that is controllable in order in each operating cycle to present a weft yarn to a respective rapier. This weft insertion mechanism is therefore provided in order in each operating cycle to insert two weft yarns simultaneously one above the other.